Water heater



L. J. MORGAN March 1, 1966 WATER HEATER 2 Sheets-Sheet 1 Filed Jan. 27,1964 INVENTOR. LEMUEL J. MORGAN ATTORNEYS March 1, 1966 J. MORGAN3,237,634

WATER HEATER Filed Jan. 27, 1964 2 Sheets-Sheet 2 INVENTOR LEMl/EL J.MORGAN A ZTOPNEYS United States Patent 3,237,684 WATER HEATER Lemuel J.Morgan, Stroudsburg, Pa., assignor toThe Patterson-Kelley Co. Inc., EastStroudsburg, Pa. Filed Jan. 27, 1964, Ser. No. 340,347 4 Claims. (Cl.165-39) This invention relates to industrial water heaters, and moreparticularly to steam-energized heaters of the type having a steam tubebundle immersed in a water tank acting as a combination water heater andtemporary storage facility. Such devices of the prior art typicallycomprise a closed cylindrical or other shaped tank ported through a sidewall .portion to receive in slip-fitted relation therein the steamcarrying tube bundle; along with appropriate cold water inlet and hotwater outlet and accessory connections usually arranged so that the coldwater enters at the bottom of the tank and hot water is drawn off at thetop. However, such arrangements usually permit the cold water toimmediately spread and disperse throughout the tank; and in spite ofvarious baflle arrangements some portions of the inlet water usuallyfind their way into the upper storage level of the tank Without comingWithin the heat exchange range of the heating tubes. Hence cold waterpockets or stratifications of relatively hot and cold water tend tooccur in the storage area, in many cases to such extent as to requirethe use of agitation or recirculation devices with a view to deliveringwater at uniform temperature. Previous efforts to eliminate thedifficulties and disadvantages referred to hereinabove have involvedundesirably increased costs of manufacture, operation, and maintenance,while at the same time falling short of attainment of maximum heattransfer rate and heat exchange efliciency; and it is a primary objectof the present invention to provide an improved water heater designedspecifically to avoid the difficulties and disadvantages mentionedhereinabove.

Another object is to provide an improved heater design as aforesaid; theparts of which may be easily and inexpensively fabricated and assembledto provide an overall structurally simplified mechanism of improvedperformance capabilities.

Another object is to provide an improved heater design as aforesaidwhich in operation is productive of a substantially increased heattransfer rate.

Another object is to provide an improved heater as aforesaid which willoperate at an increased degree of heat exchange efliciency.

Still another object is to provide a heater as aforesaid which ofiers animproved output water temperature control facility.

Other objects and advantages of the invention will become apparent fromthe following specification and the accompanying drawing wherein:

FIG. 1 is a fragmentary vertical sectional view through a water heaterembodying the present invention;

FIG. 2 is a fragmentary front elevational view thereof; and

FIG. 3 is a fragmentary sectional view taken as suggested by line 3-3 ofFIG. 1.

In the drawing herewith the invention is illustrated as being embodiedby way of example, in an upright type heating and storage tank system,wherein a vertically elongate tank is employed; but it will beappreciated that it may be employed with equal facility in connectionwith any other type tank arrangement. The invention is embodied within anovel combination tank bonnet and heating tube bundle shroud which isdesignated generally by the numeral 12. The device is readily fabricatedas shown, by simple sand foundry casting techniques or the like, tocomprise in combination, an integrally formed bowl-shaped body portion14 closing the bottom 3,237,684 Patented Mar. 1, 1966 end of the tank10, and a horizontally disposed tube shroud portion 16 extending bothinto the body portion 14 and through and beyond the forward wallthereof. At its upper level in the region of the tank 10 the bodyportion 14 is shaped as indicated at 17 to complement the sectionalprofile of the tank 10 and is provided with a flange 18 for boltedconnection to the bottom flange portion 19 of the tank 10. As shown, theshroud portion 16 of the device is of circular section form andterminates at its outer end in a flanged face 20 against which rests atube sheet 22 backed up by a bonnet 24 having a flange 26 clamped as bymeans of bolts 27 to the shroud flange; thus holding the parts in theassembled relation shown.

The shroud portion 16 of the device houses a bundle of return bentheating tubes of which the upper flights are designated 30 and the lowerflights are indicated at 32. The tubes are connected at their forwardends into the tube sheet 22 in conventional manner. The bonnet 24 ishorizontally partitioned as indicated at 34 (FIG. 2); and thus it willbe understood that live steam entering the bonnet as at 36 will passfirst through the upper portions 30 of the tubes and then return throughtheir lower portions 32 for discharge from the bonnet as indicated at38. Thus, the discharge of spent steam may go from conduit 38 to a steamtrap and condensate outlet (not shown) or the like, and any suitableinlet steam control devices (also not shown) will of course be used inconnection with the bonnet inlet conduit 36.

Whereas the main section of the shroud 16 is of circular cross sectionit is a particular feature of the present invention that the bottomthereof adjacent the return bend portions of the tubes is shaped tomerge as indicated at 40 into the contour of the bowl shape of the bodyportion 14 and in a form closely complementing the profiles of the bentends of the tubes. Furthermore, the top portion of the tube shroudadjacent the rear end of the device is cut short as shown at 42 (FIG. 1)of the rear body wall to thereby provide an open water passagewaythrough the top rear end portion of the shroud device just above thereturn bend end portions of the tubes. The cold water inlet is disposedat the front lower portion of the tube shroud such as by means ofconduit 44 (FIG. 1), and the storage tank hot water outlet connection isindicated at 46. Thus, it will be seen that withdrawal of hot water at46 will induce inlet of raw cold water through 44 into the front lowerend of the tube shroud. Partial partitions or baffles as shown at 48 arepreferably provided to vertically traverse the interior of the shroud inalternately disposed relation so as to compel the Water traveling fromthe inlet conduit through the tube bundle to follow a zig-zag course asshown by the directional arrows; and it is to be particularly noted thatthe innermost baffle 48 closes off the upper level of the shroud andforces the water to flow under its bottom edge and thence around andupwardly through the bent end portions of the tubes, finding finalegress through the opening behind the shroud portion 40 up into thestorage tank 10. Note that throughout the entire travel of the waterthrough the shroud, until it is delivered into the storage tank it isconfined in intimate contact with the heating tubes and finally withtheir bent end convolutions. In conventional arrangements the bent endsof the tubes are not effectively employed as heat-exchange surfacesbecause in the prior arrangements the water velocity over the U-bendportions of the tubes falls off drastically. It will be seen from thedrawing herewith that in the case of the present invention the spacesprovided between and around the bent ends of the tubes, and the curvingrear end wall portion of the shroud cooperate to provide forsubstantially constant velocity of the water flow throughout the heatexchange zones. Thus a superior heat transfer effect is obtained becausean improved water flow pattern against the tube bent end portions isobtained.

Another feature of the device of the invention is that it facilitatesdisposition of a temperature sensing device such as bulb 50 (FIG. 1)just above the exit of heated water from the shroud device. Thus, thesensor is adapted to provide an improved temperature control function,because the heated water rising from below and through the constrictedexit immediately below the bulb 50 is permitted no substantial lateraldispersion before contacting the bulb. As also shown in FIG. 1, a deviceto anticipate the need for heat supply to the tube bundle may beprovided in the form of a bypass bleed conduit 52 leading from the coldwater supply conduit 44 directly into the housing of the control bulb50. Thus, whenever water is withdrawn at 46 the static pressure balanceinside the tank is disrupted and a compensatory charge of cold waterautomatically flows through conduit 44. The major portion flows into thetube bundle shroud but a minor portion flows also through bypass 52 intodirect contact with the bulb 50, thereby energizing the latter to callfor a supply of steam (or other heating device) into the heat exchangetube bundle. This avoids the time delay in heat control response thatwould otherwise be experienced if the bulb 50 waited for cooler water toreach it after flowing through the tube shroud system. The conduit 52may of course be equipped with a metering valve 54 (manually adjustable)and the bulb 50 will of course be connected to control the steam inletas through means of electrical conductors as indicated at 56. A shut-offvalve as shown at 58 may also be provided to permit disablement of thebypass system if preferred. A drain-off valve may be provided asindicated at 60 for periodic clearing of the heater shroud ofaccumulated sediments; and the customary steam pressure and storagewater temperature gauges are provided as shown at 62, 64, respectively.

It will be appreciated that in addition to providing a more efficientsystem, because of the water flow pattern through the shroud only auniformly heated stream of water will pass through the shroud exit intothe storage tank, thereby insuring against stratification or cold waterpockets in the storage water; and that although only one form of theinvention has been illustrated and described in detail herein, variouschanges may be made therein without departing from the spirit of theinvention or the scope of the following claims.

I claim:

1. A water storage and heater device comprising, in combination,

a tank having an elongate tubular side wall closed at one end and openat its other end,

a hot water withdrawal outlet at said one end of the tank for connectionto a variable-demand hot water system,

a heater bonnet detachably secured to said other end of said tank, saidheater bonnet including a tubular side wall forming a continuation ofsaid tank and an end wall closing said other end of the tank, saidheater bonnet also including an opening at one point in its side walland a shroud having an external shroud portion projecting laterallyoutwardly from said opening and an arcuate internal shroud portionprojecting inwardly from said opening, said end wall of the bonnethaving an arcuate portion opposite said arcuate internal shroud portioncooperating therewith to form an internal cylindrical continuation ofsaid external shroud portion, said internal shroud portion terminatingin closely spaced relation to that portion of said side wall of thebonnet opposite said opening to define a mouth for said shroud directedtoward and communicating with the interior of said tank,

a cold water inlet connected to said external shroud portion adjacentthat end thereof remote from the tank,

and heater means disposed within and extending throughout the length ofsaid shroud.

2. The water storage and heater device according to claim 1 includingtemperature-sensitive means within said bonnet adjacent said mouth ofthe shroud for controlling said heater means,

and a cold water bleed conduit for discharging cold water directly intothe region of said mouth when hot water is withdrawn from said tank.

3. A water storage and heater device comprising, in

combination,

an elongate tank having a hot Water outlet at one end and a heaterbonnet at its otherend, 1

said bonnet having a tubular side wall provided wit an opening thereinfor introducing cold water into the tank whenever hot water is Withdrawntherefrom, said bonnet including an arcuate end wall portion and anarcuate shroud portion cooperating to define a cylindrical shroudextending inwardly from said opening toward the side wall portion ofsaid bonnet opposite said opening, said arcuate shroud portionterminating in spaced relation to said opposite side wall portion of thebonnet to define therewith a discharge mouth for said shroud which isdirected laterally with respect to the axis of said shroud and towardsaid one end of the tank whereat the hot water outlet is located,

and heater means within said shroud.

4. The water storage and heater device as defined in claim 3 includingtemperature-sensitive means within said bonnet adjacent said mouth ofthe shroud for controlling said heater means, and a cold water bleedconduit for discharging cold water directly into the region of saidmouth when hot water is withdrawn from said tank.

References Cited by the Examiner UNITED STATES PATENTS 2,065,147 12/1936Munson et a1 165 159 X 2,279,552 4/1942 Bowman 165-161 X 2,429,408 10/1947 Earley et al 165-132 X 2,460,660 2/ 1949 Tinker l161 2,879,7493/1959 Lewy l65159 X 2,954,965 10/1960 Sebald l6572 X 3,133,590 5/1964Lowe -132 X FREDERICK L. MATTESON, JR., Primary Examiner.

KENNETH W. SPRAGUE, Examiner.

1. A WATER STORAGE AND HEATER DEVICE COMPRISING, IN COMBINATION, A TANKHAVING AN ELONGATE TUBULAR SIDE WALL CLOSED AT ONE END AND OPEN AT ITSOTHER END, A HOT WATER WITHDRAWL OUTLET AT SAID ONE END OF THE TANK FORCONNECTION TO A VARIABLE-DEMAND HOT WATER SYSTEM, A HEATER BONNETDETACHABLY SECURED TO SAID OTHER END OF SAID TANK, SAID HEATER BONNETINCLUDING A TUBULAR SIDE WALL FORMING A CONTINUATION OF SAID TANK AND ANEND WALL CLOSING SAID OTHER END OF THE TANK, SAID HEATER BONNET ALSOINCLUDING AN OPENING AT ONE POINT IN ITS SIDE WALL AND A SHROUD HAVINGAN EXTERNAL SHROUD PORTION PROJECTING LATERALLY OUTWARDLY FROM SAIDOPENING AND AN ARCUATE INTERNAL SHROUD PORTION PROJECTING INWARDLY FROMSAID OPENING, SAID END WALL OF THE BONNET HAVING AN ARCUATE PORTIONOPPOSITE SAID ARCUATE INTERNAL SHROUD PORTION COOPERATING THEREWITH TOFORM AN INTERNAL CYLINDRICAL CONTINUATION OF SAID EXTERNAL SHROUDPORTION, SAID INTERNAL SHROUD PORTION TERMINATING IN CLOSELY SPACEDRELATION TO THAT PORTION OF SAID WALL OF THE BONNET OPPOSITE SAIDOPENING